My previous airline allowed unlimited sick calls if documented with a doctor’s note. You had to see a doctor within 72 hours of calling in sick and had to turn in the original sick note by your next assignment. A sick call could only be for a maximum of 14 days. And there was limitations on who you could get a note from and what the note had to say.

If you didn’t have a doctor’s note, you got one point for each sick call. The Cheif Pilot was contractually allowed to ask for a sick note if you called before/after vacation or a holiday. After 4 in a rolling twelve calendar months, you got a verbal warning, 5 a written warning, 6 a termination warning, and theoretically after 7 you could be fired. Although I never hear of anyone actually being fired because of sick notes. Probably because lawyers would get involved. Usually they found another reason to fire pilots who they suspected they were abusing the sick call policy. Last thing, if a pilot had a no show or unable to contact for reserves, they got 2 points.